feat(backend): demo scheduler on the virtual clock — doses, missed, check-ins, scales, silence

- app/scheduler/demo.py: run_until(now) replays due and fresh events in time order: dose rows +
  med_reminder, missed after 2 h without an answer → monitoring, daily_checkin, scale_due by the
  config/modules.yaml schedules, daily monitoring pass (silence, missed doses) → reach_out/scale_due
- idempotent via scheduler_events (unique token+key); stale events are not sent; no contact without
  consent or during an open crisis
- config/scheduler.yaml: times and windows; runs while the questionnaire release is off
- POST /demo/clock/advance replays the scheduler up to the new time

Refs #13

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

config/scheduler.yaml

@@ -0,0 +1,25 @@
+# Demo scheduler on the virtual clock (#13, SPEC §8, ADR-005). Local times are in settings.tz.
+# Read by app/scheduler/demo.py; used only while the questionnaire release (intake_runtime.yaml) is off.
+#
+# Every event is delivered once (idempotency key in `scheduler_events`) and only while it is fresh: an event
+# older than its late window is not sent at all — after a long jump of the demo clock the patient does not
+# receive a pile of yesterday's reminders, and an undelivered reminder never turns into a "missed" dose.
+
+enabled: true
+tick_seconds: 30
+
+doses:
+  late_hours: 2            # reminder not delivered if the dose time is older than this
+  missed_after_hours: 2    # reminded dose without an answer → status "missed" (SPEC §8)
+
+daily_checkin:
+  time: "20:00"
+  late_hours: 4
+
+scales:
+  time: "10:00"            # scales due today (config/modules.yaml schedules) are offered from this hour
+  late_hours: 10
+
+evaluation:
+  time: "09:00"            # daily monitoring pass: silence > N days, missed doses → caring contact
+  late_hours: 15